fs/qnx4/inode.c

   1 /*
   2  * QNX4 file system, Linux implementation.
   3  *
   4  * Version : 0.2.1
   5  *
   6  * Using parts of the xiafs filesystem.
   7  *
   8  * History :
   9  *
  10  * 01-06-1998 by Richard Frowijn : first release.
  11  * 20-06-1998 by Frank Denis : Linux 2.1.99+ support, boot signature, misc.
  12  * 30-06-1998 by Frank Denis : first step to write inodes.
  13  */
  14
  15 #include <linux/config.h>
  16 #include <linux/module.h>
  17 #include <linux/types.h>
  18 #include <linux/string.h>
  19 #include <linux/errno.h>
  20 #include <linux/slab.h>
  21 #include <linux/qnx4_fs.h>
  22 #include <linux/fs.h>
  23 #include <linux/locks.h>
  24 #include <linux/init.h>
  25 #include <linux/highuid.h>
  26 #include <linux/smp_lock.h>
  27
  28 #include <asm/uaccess.h>
  29
  30 #define QNX4_VERSION  4
  31 #define QNX4_BMNAME   ".bitmap"
  32
  33 static struct super_operations qnx4_sops;
  34
  35 #ifdef CONFIG_QNX4FS_RW
  36
  37 int qnx4_sync_inode(struct inode *inode)
  38 {
  39         int err = 0;
  40 # if 0
  41         struct buffer_head *bh;
  42
  43         bh = qnx4_update_inode(inode);
  44         if (bh && buffer_dirty(bh))
  45         {
  46                 ll_rw_block(WRITE, 1, &bh);
  47                 wait_on_buffer(bh);
  48                 if (buffer_req(bh) && !buffer_uptodate(bh))
  49                 {
  50                         printk ("IO error syncing qnx4 inode [%s:%08lx]\n",
  51                                 kdevname(inode->i_dev), inode->i_ino);
  52                         err = -1;
  53                 }
  54                 brelse (bh);
  55         } else if (!bh) {
  56                 err = -1;
  57         }
  58 # endif
  59
  60         return err;
  61 }
  62
  63 static void qnx4_delete_inode(struct inode *inode)
  64 {
  65         QNX4DEBUG(("qnx4: deleting inode [%lu]\n", (unsigned long) inode->i_ino));
  66         lock_kernel();
  67         inode->i_size = 0;
  68         qnx4_truncate(inode);
  69         qnx4_free_inode(inode);
  70         unlock_kernel();
  71 }
  72
  73 static void qnx4_write_super(struct super_block *sb)
  74 {
  75         QNX4DEBUG(("qnx4: write_super\n"));
  76         sb->s_dirt = 0;
  77 }
  78
  79 static void qnx4_write_inode(struct inode *inode, int unused)
  80 {
  81         struct qnx4_inode_entry *raw_inode;
  82         int block, ino;
  83         struct buffer_head *bh;
  84         ino = inode->i_ino;
  85
  86         QNX4DEBUG(("qnx4: write inode 1.\n"));
  87         if (inode->i_nlink == 0) {
  88                 return;
  89         }
  90         if (!ino) {
  91                 printk("qnx4: bad inode number on dev %s: %d is out of range\n",
  92                        kdevname(inode->i_dev), ino);
  93                 return;
  94         }
  95         QNX4DEBUG(("qnx4: write inode 2.\n"));
  96         block = ino / QNX4_INODES_PER_BLOCK;
  97         lock_kernel();
  98         if (!(bh = sb_bread(inode->i_sb, block))) {
  99                 printk("qnx4: major problem: unable to read inode from dev "
 100                        "%s\n", kdevname(inode->i_dev));
 101                 unlock_kernel();
 102                 return;
 103         }
 104         raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
 105             (ino % QNX4_INODES_PER_BLOCK);
 106         raw_inode->di_mode  = cpu_to_le16(inode->i_mode);
 107         raw_inode->di_uid   = cpu_to_le16(fs_high2lowuid(inode->i_uid));
 108         raw_inode->di_gid   = cpu_to_le16(fs_high2lowgid(inode->i_gid));
 109         raw_inode->di_nlink = cpu_to_le16(inode->i_nlink);
 110         raw_inode->di_size  = cpu_to_le32(inode->i_size);
 111         raw_inode->di_mtime = cpu_to_le32(inode->i_mtime);
 112         raw_inode->di_atime = cpu_to_le32(inode->i_atime);
 113         raw_inode->di_ctime = cpu_to_le32(inode->i_ctime);
 114         raw_inode->di_first_xtnt.xtnt_size = cpu_to_le32(inode->i_blocks);
 115         mark_buffer_dirty(bh);
 116         brelse(bh);
 117         unlock_kernel();
 118 }
 119
 120 #endif
 121
 122 static struct super_block *qnx4_read_super(struct super_block *, void *, int);
 123 static void qnx4_put_super(struct super_block *sb);
 124 static void qnx4_read_inode(struct inode *);
 125 static int qnx4_remount(struct super_block *sb, int *flags, char *data);
 126 static int qnx4_statfs(struct super_block *, struct statfs *);
 127
 128 static struct super_operations qnx4_sops =
 129 {
 130         read_inode:     qnx4_read_inode,
 131 #ifdef CONFIG_QNX4FS_RW
 132         write_inode:    qnx4_write_inode,
 133         delete_inode:   qnx4_delete_inode,
 134 #endif
 135         put_super:      qnx4_put_super,
 136 #ifdef CONFIG_QNX4FS_RW
 137         write_super:    qnx4_write_super,
 138 #endif
 139         statfs:         qnx4_statfs,
 140         remount_fs:     qnx4_remount,
 141 };
 142
 143 static int qnx4_remount(struct super_block *sb, int *flags, char *data)
 144 {
 145         struct qnx4_sb_info *qs;
 146
 147         qs = &sb->u.qnx4_sb;
 148         qs->Version = QNX4_VERSION;
 149         if (*flags & MS_RDONLY) {
 150                 return 0;
 151         }
 152         mark_buffer_dirty(qs->sb_buf);
 153
 154         return 0;
 155 }
 156
 157 struct buffer_head *qnx4_getblk(struct inode *inode, int nr,
 158                                  int create)
 159 {
 160         struct buffer_head *result = NULL;
 161
 162         if ( nr >= 0 )
 163                 nr = qnx4_block_map( inode, nr );
 164         if (nr) {
 165                 result = sb_getblk(inode->i_sb, nr);
 166                 return result;
 167         }
 168         if (!create) {
 169                 return NULL;
 170         }
 171 #if 0
 172         tmp = qnx4_new_block(inode->i_sb);
 173         if (!tmp) {
 174                 return NULL;
 175         }
 176         result = sb_getblk(inode->i_sb, tmp);
 177         if (tst) {
 178                 qnx4_free_block(inode->i_sb, tmp);
 179                 brelse(result);
 180                 goto repeat;
 181         }
 182         tst = tmp;
 183 #endif
 184         inode->i_ctime = CURRENT_TIME;
 185         mark_inode_dirty(inode);
 186         return result;
 187 }
 188
 189 struct buffer_head *qnx4_bread(struct inode *inode, int block, int create)
 190 {
 191         struct buffer_head *bh;
 192
 193         bh = qnx4_getblk(inode, block, create);
 194         if (!bh || buffer_uptodate(bh)) {
 195                 return bh;
 196         }
 197         ll_rw_block(READ, 1, &bh);
 198         wait_on_buffer(bh);
 199         if (buffer_uptodate(bh)) {
 200                 return bh;
 201         }
 202         brelse(bh);
 203
 204         return NULL;
 205 }
 206
 207 int qnx4_get_block( struct inode *inode, long iblock, struct buffer_head *bh, int create )
 208 {
 209         unsigned long phys;
 210
 211         QNX4DEBUG(("qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));
 212
 213         phys = qnx4_block_map( inode, iblock );
 214         if ( phys ) {
 215                 // logical block is before EOF
 216                 bh->b_dev     = inode->i_dev;
 217                 bh->b_blocknr = phys;
 218                 bh->b_state  |= (1UL << BH_Mapped);
 219         } else if ( create ) {
 220                 // to be done.
 221         }
 222         return 0;
 223 }
 224
 225 unsigned long qnx4_block_map( struct inode *inode, long iblock )
 226 {
 227         int ix;
 228         long offset, i_xblk;
 229         unsigned long block = 0;
 230         struct buffer_head *bh = 0;
 231         struct qnx4_xblk *xblk = 0;
 232         struct qnx4_inode_info *qnx4_inode = &inode->u.qnx4_i;
 233         qnx4_nxtnt_t nxtnt = le16_to_cpu(qnx4_inode->i_num_xtnts);
 234
 235         if ( iblock < le32_to_cpu(qnx4_inode->i_first_xtnt.xtnt_size) ) {
 236                 // iblock is in the first extent. This is easy.
 237                 block = le32_to_cpu(qnx4_inode->i_first_xtnt.xtnt_blk) + iblock - 1;
 238         } else {
 239                 // iblock is beyond first extent. We have to follow the extent chain.
 240                 i_xblk = le32_to_cpu(qnx4_inode->i_xblk);
 241                 offset = iblock - le32_to_cpu(qnx4_inode->i_first_xtnt.xtnt_size);
 242                 ix = 0;
 243                 while ( --nxtnt > 0 ) {
 244                         if ( ix == 0 ) {
 245                                 // read next xtnt block.
 246                                 bh = sb_bread(inode->i_sb, i_xblk - 1);
 247                                 if ( !bh ) {
 248                                         QNX4DEBUG(("qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
 249                                         return -EIO;
 250                                 }
 251                                 xblk = (struct qnx4_xblk*)bh->b_data;
 252                                 if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
 253                                         QNX4DEBUG(("qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
 254                                         return -EIO;
 255                                 }
 256                         }
 257                         if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) {
 258                                 // got it!
 259                                 block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1;
 260                                 break;
 261                         }
 262                         offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size);
 263                         if ( ++ix >= xblk->xblk_num_xtnts ) {
 264                                 i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
 265                                 ix = 0;
 266                                 brelse( bh );
 267                                 bh = 0;
 268                         }
 269                 }
 270                 if ( bh )
 271                         brelse( bh );
 272         }
 273
 274         QNX4DEBUG(("qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
 275         return block;
 276 }
 277
 278 static int qnx4_statfs(struct super_block *sb, struct statfs *buf)
 279 {
 280         buf->f_type    = sb->s_magic;
 281         buf->f_bsize   = sb->s_blocksize;
 282         buf->f_blocks  = le32_to_cpu(sb->u.qnx4_sb.BitMap->di_size) * 8;
 283         buf->f_bfree   = qnx4_count_free_blocks(sb);
 284         buf->f_bavail  = buf->f_bfree;
 285         buf->f_namelen = QNX4_NAME_MAX;
 286
 287         return 0;
 288 }
 289
 290 /*
 291  * Check the root directory of the filesystem to make sure
 292  * it really _is_ a qnx4 filesystem, and to check the size
 293  * of the directory entry.
 294  */
 295 static const char *qnx4_checkroot(struct super_block *sb)
 296 {
 297         struct buffer_head *bh;
 298         struct qnx4_inode_entry *rootdir;
 299         int rd, rl;
 300         int i, j;
 301         int found = 0;
 302
 303         if (*(sb->u.qnx4_sb.sb->RootDir.di_fname) != '/') {
 304                 return "no qnx4 filesystem (no root dir).";
 305         } else {
 306                 QNX4DEBUG(("QNX4 filesystem found on dev %s.\n", kdevname(sb->s_dev)));
 307                 rd = le32_to_cpu(sb->u.qnx4_sb.sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
 308                 rl = le32_to_cpu(sb->u.qnx4_sb.sb->RootDir.di_first_xtnt.xtnt_size);
 309                 for (j = 0; j < rl; j++) {
 310                         bh = sb_bread(sb, rd + j);      /* root dir, first block */
 311                         if (bh == NULL) {
 312                                 return "unable to read root entry.";
 313                         }
 314                         for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) {
 315                                 rootdir = (struct qnx4_inode_entry *) (bh->b_data + i * QNX4_DIR_ENTRY_SIZE);
 316                                 if (rootdir->di_fname != NULL) {
 317                                         QNX4DEBUG(("Rootdir entry found : [%s]\n", rootdir->di_fname));
 318                                         if (!strncmp(rootdir->di_fname, QNX4_BMNAME, sizeof QNX4_BMNAME)) {
 319                                                 found = 1;
 320                                                 sb->u.qnx4_sb.BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL );
 321                                                 if (!sb->u.qnx4_sb.BitMap) {
 322                                                         brelse (bh);
 323                                                         return "not enough memory for bitmap inode";
 324                                                 }
 325                                                 memcpy( sb->u.qnx4_sb.BitMap, rootdir, sizeof( struct qnx4_inode_entry ) );     /* keep bitmap inode known */
 326                                                 break;
 327                                         }
 328                                 }
 329                         }
 330                         brelse(bh);
 331                         if (found != 0) {
 332                                 break;
 333                         }
 334                 }
 335                 if (found == 0) {
 336                         return "bitmap file not found.";
 337                 }
 338         }
 339         return NULL;
 340 }
 341
 342 static struct super_block *qnx4_read_super(struct super_block *s,
 343                                            void *data, int silent)
 344 {
 345         struct buffer_head *bh;
 346         kdev_t dev = s->s_dev;
 347         struct inode *root;
 348         const char *errmsg;
 349
 350         set_blocksize(dev, QNX4_BLOCK_SIZE);
 351         s->s_blocksize = QNX4_BLOCK_SIZE;
 352         s->s_blocksize_bits = QNX4_BLOCK_SIZE_BITS;
 353
 354         /* Check the superblock signature. Since the qnx4 code is
 355            dangerous, we should leave as quickly as possible
 356            if we don't belong here... */
 357         bh = sb_bread(s, 1);
 358         if (!bh) {
 359                 printk("qnx4: unable to read the superblock\n");
 360                 goto outnobh;
 361         }
 362         if ( le32_to_cpu( *(__u32*)bh->b_data ) != QNX4_SUPER_MAGIC ) {
 363                 if (!silent)
 364                         printk("qnx4: wrong fsid in superblock sector.\n");
 365                 goto out;
 366         }
 367         s->s_op = &qnx4_sops;
 368         s->s_magic = QNX4_SUPER_MAGIC;
 369 #ifndef CONFIG_QNX4FS_RW
 370         s->s_flags |= MS_RDONLY;        /* Yup, read-only yet */
 371 #endif
 372         s->u.qnx4_sb.sb_buf = bh;
 373         s->u.qnx4_sb.sb = (struct qnx4_super_block *) bh->b_data;
 374
 375
 376         /* check before allocating dentries, inodes, .. */
 377         errmsg = qnx4_checkroot(s);
 378         if (errmsg != NULL) {
 379                 if (!silent)
 380                         printk("qnx4: %s\n", errmsg);
 381                 goto out;
 382         }
 383
 384         /* does root not have inode number QNX4_ROOT_INO ?? */
 385         root = iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
 386         if (!root) {
 387                 printk("qnx4: get inode failed\n");
 388                 goto out;
 389         }
 390
 391         s->s_root = d_alloc_root(root);
 392         if (s->s_root == NULL)
 393                 goto outi;
 394
 395         brelse(bh);
 396
 397         return s;
 398
 399       outi:
 400         iput(root);
 401       out:
 402         brelse(bh);
 403       outnobh:
 404
 405         return NULL;
 406 }
 407
 408 static void qnx4_put_super(struct super_block *sb)
 409 {
 410         kfree( sb->u.qnx4_sb.BitMap );
 411         return;
 412 }
 413
 414 static int qnx4_writepage(struct page *page)
 415 {
 416         return block_write_full_page(page,qnx4_get_block);
 417 }
 418 static int qnx4_readpage(struct file *file, struct page *page)
 419 {
 420         return block_read_full_page(page,qnx4_get_block);
 421 }
 422 static int qnx4_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
 423 {
 424         return cont_prepare_write(page,from,to,qnx4_get_block,
 425                 &page->mapping->host->u.qnx4_i.mmu_private);
 426 }
 427 static int qnx4_bmap(struct address_space *mapping, long block)
 428 {
 429         return generic_block_bmap(mapping,block,qnx4_get_block);
 430 }
 431 struct address_space_operations qnx4_aops = {
 432         readpage: qnx4_readpage,
 433         writepage: qnx4_writepage,
 434         sync_page: block_sync_page,
 435         prepare_write: qnx4_prepare_write,
 436         commit_write: generic_commit_write,
 437         bmap: qnx4_bmap
 438 };
 439
 440 static void qnx4_read_inode(struct inode *inode)
 441 {
 442         struct buffer_head *bh;
 443         struct qnx4_inode_entry *raw_inode;
 444         int block, ino;
 445
 446         ino = inode->i_ino;
 447         inode->i_mode = 0;
 448
 449         QNX4DEBUG(("Reading inode : [%d]\n", ino));
 450         if (!ino) {
 451                 printk("qnx4: bad inode number on dev %s: %d is out of range\n",
 452                        kdevname(inode->i_dev), ino);
 453                 return;
 454         }
 455         block = ino / QNX4_INODES_PER_BLOCK;
 456
 457         if (!(bh = sb_bread(inode->i_sb, block))) {
 458                 printk("qnx4: major problem: unable to read inode from dev "
 459                        "%s\n", kdevname(inode->i_dev));
 460                 return;
 461         }
 462         raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
 463             (ino % QNX4_INODES_PER_BLOCK);
 464
 465         inode->i_mode    = le16_to_cpu(raw_inode->di_mode);
 466         inode->i_uid     = (uid_t)le16_to_cpu(raw_inode->di_uid);
 467         inode->i_gid     = (gid_t)le16_to_cpu(raw_inode->di_gid);
 468         inode->i_nlink   = le16_to_cpu(raw_inode->di_nlink);
 469         inode->i_size    = le32_to_cpu(raw_inode->di_size);
 470         inode->i_mtime   = le32_to_cpu(raw_inode->di_mtime);
 471         inode->i_atime   = le32_to_cpu(raw_inode->di_atime);
 472         inode->i_ctime   = le32_to_cpu(raw_inode->di_ctime);
 473         inode->i_blocks  = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
 474         inode->i_blksize = QNX4_DIR_ENTRY_SIZE;
 475
 476         memcpy(&inode->u.qnx4_i, (struct qnx4_inode_info *) raw_inode, QNX4_DIR_ENTRY_SIZE);
 477         if (S_ISREG(inode->i_mode)) {
 478                 inode->i_op = &qnx4_file_inode_operations;
 479                 inode->i_fop = &qnx4_file_operations;
 480                 inode->i_mapping->a_ops = &qnx4_aops;
 481                 inode->u.qnx4_i.mmu_private = inode->i_size;
 482         } else if (S_ISDIR(inode->i_mode)) {
 483                 inode->i_op = &qnx4_dir_inode_operations;
 484                 inode->i_fop = &qnx4_dir_operations;
 485         } else if (S_ISLNK(inode->i_mode)) {
 486                 inode->i_op = &page_symlink_inode_operations;
 487                 inode->i_mapping->a_ops = &qnx4_aops;
 488                 inode->u.qnx4_i.mmu_private = inode->i_size;
 489         } else
 490                 printk("qnx4: bad inode %d on dev %s\n",ino,kdevname(inode->i_dev));
 491         brelse(bh);
 492 }
 493
 494 static DECLARE_FSTYPE_DEV(qnx4_fs_type, "qnx4", qnx4_read_super);
 495
 496 static int __init init_qnx4_fs(void)
 497 {
 498         printk("QNX4 filesystem 0.2.2 registered.\n");
 499         return register_filesystem(&qnx4_fs_type);
 500 }
 501
 502 static void __exit exit_qnx4_fs(void)
 503 {
 504         unregister_filesystem(&qnx4_fs_type);
 505 }
 506
 507 EXPORT_NO_SYMBOLS;
 508
 509 module_init(init_qnx4_fs)
 510 module_exit(exit_qnx4_fs)
 511 MODULE_LICENSE("GPL");
 512